Improvement in let-off mechanisms for looms



n. K EATING. LET-OFF MECHANISMFOR LOOMS.

No. 192,514. Patented June 26,1877.

DANIEL E. 'KEATING, OF LOWELL, MASS, ASS IGNOR TO HIMSELF, DAV IDPIOKMAN, AND GEORGE W. GROSS, OF SAME PLACE.

IMPROVEMENT IN LET-OFF MECHANISMS FOR LOOMS.

Specification forming part of Letters Patent No.

192,514, dated June 26, 1877; application filed May 19, 1877.

To all whom it may concern Be it known that I, DANIEL E. KEATING, ofLowell, in the county of Middlesex and State of Massachusetts, haveinvented an Improvement in Let-Ofi' Mechanism for Looms, of which thefollowing is a specification:

This invention relates to mechanism for letting off the warp as it isrequired in weaving.

The invention consists in the combination, with a whip-roll, operated bya weight, of a pawl connected with and operated directly by thewhip-roll, to engage a ratchet-wheel on a worm-shaft, engaged directlywith a pinion on the warp-beam.

By devices connected in such manner, and operated positively accordingto the tension on the warps, the latter may be retained uniformly undera certain amount of tension at all positions of the whip-roll, and forevery pick from the commencement of a full warpv until it is woven offor unwound to its end. The tension of the warp is not increased by theblow of the lay when beating in the filling, and is not varied by thereduction of the size of the yarn-beam. Also, in so pivoting the worm todrive the warp-beam that it may be thrown out of operative engagementwith the worm-pinion on the warp-beam whenever the shuttle becomescaught in the shed.

This construction obviates breaking th Warp and loom.

Figure 1 represents in side elevation su'fficient portions of a loom todelineate my invention, and Fig. 2 a sectional detail thereof.

The frame a of the loom may be of any usual form, and may be suppliedwith crank-shaft, lay, and shedding mechanism of any usual construction.

The warp b on'the warp-beam o is extended over the rod d, which is inthis instance the center of motion of the whip-roller frame, thence overthe whip-roller 6, through eyes f of the harnesses, and woven intocloth. It then passes over the breast-beam g, and is wound upon thetake-up beam h. The whip-roller e is supported between arms z attachedto the shaft d, mounted on the usual whip-roll brackets at the rear ofloom. These arms are provided at their outer ends with weights j.

The yarn bearing upon the whip-roll is by the weight or weightsconstantly kept pressed upward with a certain fixed amountof tensionunder all conditions of the warp and positions of the whip-roller,whether the lay is just beating up the filling, or whether the warp-beamcontains more or less warp. V

This, it is obvious, would not be thecase if a spring was used insteadof the weight, for the power of the spring is changed at each variationof position of the whip-roller, and also by variations in temperatureand temper.

One of the arms '5 has pivoted upon it a disengaging rod or finger, k,and in this instance of my invention I have pivoted upon the rod is, at2, the let-off operating-pawl l, but it is obvious that it might be justas well pivoted directly upon the arm 5. (See dotted lines.) Theconstruction shown in the drawing is the cheaper. ratchet, m, on ashaft, n, supported in bearings o projecting from a plate pivoted at pto a stationary part of the loom-frame. The shaft n is provided with aworm, q, adapted to engage a pinion, 1",, attached to the yarnbeam. Theworm-gear is held up in engagement with the teeth of the pinion by meansof a catch, 8, which engages aprojection, t, on the bearing-frame. (SeeFig. 2.) The weight j is adapted to the yarn employed and the clothbeing woven, so as to hold it under a certain definite tension. Thewhip-roller is depressed from its upward to alower position each timethat the reed beats up the filling. As the cloth is formed and movedforward the warp depresses the whip-roller, so that as it rises andfalls under the action of the beat of the lay at the cloth-making point,and the formation of the sheds, it rises not quite so high and descendsa little lower, until it descends far enough for the pawl to pass overand engage a tooth of the ratchet, and then as the whip-roll rises underthe action of the weight it rotates the ratchet and its shaft one tooth,causing the worm-gear to rotate the warpbeam, and thus let off the warp,so that the whip-roll again ascends substantially to its highest point,ready to be again gradually depressed, as just before described.

In this way it is obvious that the proper amount of yarn will be let offat the proper The pawl lengages the teeth of a 2 li fih i time, and itwill be let off evenly, one tooth after another of the ratchet beingsuccessively engaged by the pawl.

In this my improved let-off the tension on the warp is kept constant bythe direct action of a weight, as contradistinguished from a spring,which is liable to variations in power under varying temperature anddegrees of compression.

On a loom provided with this let-off, and in practical operation,thirty-six successive cuts of cloth-three full warps--have been wovenfrom like warp and filling with a variation of less than one per cent.in weight. The power applied to cause the pawl to move the ratchet andlet off the warp comes directly from the weight or weights j, and thepower to lower the pawl is exerted by the Warp on the whip-roll, withwhich the pawl is connected, and in unison with which it rises andfalls.

In case the shuttle becomes caught in the shed, then the warp must hesuddenly let off, or the warp or the loom will be broken. To preventinjury of warp or loom at such an accident, I have provided a leg, it,it having a foot consisting of a heel, 3, and a toe, 4, so arranged thatwhen the whip-roller is sudden ly depressed by unnatural strain on thewarp the heel 3 will strike the catch 8 and release it from the part tof the bearing-frame of the shaft n, and thetoo 4: will simultaneouslystrike the top of and push down the shaft a, its pivoted bearingportions turning on the pivot 1), permitting the worm to free itselffrom the pinion r, and the warp-beam to turn freely.

When the loom is again ready to be started the bearing portionssustaining the shaft n are again brought into operative position andcaught by the catch. The connection between the whip-roll and theratchet for moving the worm-shaft and warp-beam is direct and positivewithout the intervention of a spring, and the movement of the pawl isderived solely from the movement of the whip-roll.

Instead of the whip-roll and catch shown, I

might employ any other well-known and equivalent devices.

The take-up is in this instance shown as controlled by a lever, y, aweight, w, a tappet, 6, a pawl, 00, and a ratchet, 5, it being on a shaft provided, as usual, with a pinion in gear with the pinion 8 in thetake-up roller.

I claim- 1. The warp-beain and its gear, the shaft n and its worm-wheel,placed at right angles to the axis of the warp-beam and the ratchet onthe shaft n, in combination with the whip-roll and the suspended weightand pawl, adapted to operate as described, to move the warpbeampositively to let off the warp as the whip-roll rises.

2. The warp-beam and its operating-gear, the latter supported in apivoted frame, in combination with devices adapted to disengage theoperative-gearfrom the warp-beam, to release it when the shuttle becomescaught in the shed.

3. The whip-roll, controlled as to its downward position by the strainon the warp, and the leg it connected therewith, in combination with ashaft supported in pivoted bearings, and adapted to operate thewarp-beam, whereby, when the strain on the warp is excessive, thewarp-beam is left free to rotate, substantially as described.

4. The combination, with the lay to beat up the filling and strain thewarp according to the diameter of the filling, a whip-roller, and asuspended weight to elevate it in opposition to the strain of the warpafter the blow of the lay, of a positively-operating catch-pawl gear andworm, whereby the said mechanism is adapted to move the screw-shaft tooperate the warp-beam positively to let 01f the warp, substantially asdescribed.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

DANIEL E. KEATING.

Witnesses:

G. W. GREGORY, S. B. KIDDEB.

